SU753568A1 - Tap for cutting precise threads - Google Patents

Description

one

The invention relates to metal working, namely threading with taps.

A tap is known for cutting exact threads from a first thread, the tooth of which is barrel-shaped in arc sections l.

The optimal geometry of the teeth of this tap is obtained due to the fact that the cutting edges of the tap are kept sharp as in a conventional tap, while the leading ones are barrel-shaped, are not visible in arc sections and are in contact with the surface of the thread. As a result of their rounding off on the cutting teeth x and underestimation on the calibrating (leading) teeth x in contact with the thread profile of the part there is a platform.

Such a tap, supported by these pads, will very reliably orient and inform the whole tap body of the movement with strict napeiMeTpa of screw movement.

This tap is closest to the invention in its technical essence and the achieved result.

The disadvantage of it is that it turns out to be completely technologically impracticable for the conditions. fine precision thread machining.

The aim of the invention is to ensure the formation of small sized precision threads.

This goal is achieved by

10 that on each tooth of the intake cone the cutting edge is shifted to the back surface of the pen and performed on the most convex part of the tooth due to the underestimation of the outer diameter of the tap

15 by an amount greater than the thickness of the slice 4.-6 times.

FIG. 1 depicts the described tap in isometry with barrel shaped teeth in arc sections.

20

in fig. 2 - tap with four feathers m. Mi (there may be three or more), general view} in FIG. 3 - section A-A of FIG. 2 in FIG. 4 - working tooth of the intake cone; in fig. 5-section

25 bb fig. four.

The tap consists of the guiding part 1, the intake cone / 2, the calibrating part 3 and the tail gun 4.

Claims (1)

On each tooth 5 of the intake cone 2, the cutting edge 6 is displaced to the back of the surface 7 of the feather 8 and is made on the most convex 9 part of the tooth due to understating 2 liters. 10 outer diameter tap on the value, exceeding the thickness of the slice 4-6 times. During operation, the tap, screwing in detail, removes the chips with its cutting edges, and below the cutting zone, it turns out to be reliably oriented by the ObSM barrel-shaped profile of the teeth in the thread being cut. This eliminates the possibility of undercutting the profile of the thread being cut. The described matshil has good cutting properties, as well as reliable orientation in the cutting threads. Therefore, it has become possible to use it for cutting fine, fine-sized precision threads. To manufacture the tap of the proposed design, a conventional cam is used with a decay to both sides of the maximum radius. Outside diameter can be done on a conventional sharpening machine before sanding the thread to prevent burrs on the cutting edges. Claims for cutting fine threads from the first thread, the teeth of which are barrel-shaped in arc sections, characterized in that, in order to ensure the formation of small-sized precision threads, on each tooth of the suction cone the cutting edge is offset to the back surface of the pen and made on the convex part of the tooth due to the underestimation of the outer diameter of the tap by an amount exceeding the thickness of the slice by 4-6 times. Sources of information taken into account during the examination 1. V. Matveev. Fundamentals of increasing the accuracy of machining threaded surfaces of parts with multi-blade measuring tools. Thesis for the degree of Doctor of Technical Sciences. M., 1970, pp.309-311, fig. 101. ff